Bar stock and reinforcing bar



April 1947- o. WENNBERG ET AL 2,413,333

BAR STOCK AND REINFORCING BAR Filed Sept. 8, 1945 w .T a A m M 2 50PRIOR AIQT INVFNTOHS. TA/vmbe Patented Apr. 1, 1947 BAR STOCK ANDREINFORCING BAR Odd Wennberg, Manhasset, and Joseph D. Stites,

New York, N. Y., assignors to Wegner Machinery Corporation, Long IslandCity, N. Y., a corporation of New York Application September 8, 1945,Serial No. 615,226

3 Claims. 1

This invention relates to-reinforcing bars for for use in concretestructures and the like, and particularly to that type of bar whichcomprises two rod-like sections joined in substantially parallelalignment by an integral intermediate Section, or web, of lessercross-sectional area than either of said rod-like sections, which typeof bar is twisted around its longitudinal axis before use to form, ineffect, a helical structure comprising two helices having a common axis.The use and purpose of such bar and the reasons for twisting the sameare all well known, and it is likewise well known to provide on thistype of bar ribs arranged on the outer surfaces of the bar, usuallytransversely, diagonally or spirally thereof, hereincalled transverseribs, for the express purpose of increasing the strength of the bond between the bar and the concrete or like material in which it is set orcontained.

An object of this invention is to provide a bar stock of the above typewhich, when twisted and used as a reinforcing element, forms with theconcrete or similar substance in which it is set a bond of greatstrength. i

A further object of the invention is to provide a twisted reinforcingbar of the type above described having such relation between itselements that the action of corrosive elements in the concrete in whichthe bar is set will be minimized.

Other objects and advantages will be apparent from the followingdescription of the invention with respect to the specific embodimentsthereof which are illustrated in the attached drawing:

In the drawing:

Fig. 1 is a plan view of bar stock, before the twisting operation,embodying the principles of this invention;

Fig. 2 is a cross-sectional view of the bar stock shown in Fig. 1;

Fig. 3 is a side View of the bar shownin Fig. 1;

Fig. 4 is a plan view of another bar stock, be-

fore the twisting operation, embodying the prin- Fig. is a perspectiveview of bar stock, such as that shown in Fig. 1 after it has beentwisted into a reinforcing element;

Fig. 11 is a perspective view of a portion of a bar twisted from stockof the type illustrated in Fig. 9.

Referring to the drawings, the bar shown in Figs. 1 to 6, inclusive,embodies thebasic elements representative of the type of bar abovedescribed which has been used or proposed for use as a reinforcingelement in concrete or like struc-, tures. The bar comprises the tworod-like sections 15 which are joined in substantially parallelalignment by the intermediate section or web Hi. This web has across-sectional area which is less than that of either of the rod-likesections. The

rod-like sections are usually roughly, or approximately, circular incross-section, by which is meant that they are circular, elliptical orovate in shape, the exact shape forming no part of this invention andvarying somewhat according to the specific method of manufacture, whichis usually some type of rolling process. The web 16 may bear theproportion shown in the drawing to the rod-like sections l5, or it maybe thicker or wider, its specific shape and size being no part of thepresent invention. It will be noted that the general shape formed by theweb section and the tworod-like sections is'roughly that of a dumbbell,and many different and specific shapes of this dumbbell form have benshown and described in the art. Running along the outer surface of eachrod-like section I 5 and longitudinally thereof is the longitudinal rib11. It is usually present in reinforcing bars of the type here underdiscussion because the manufacture of the bar by rolling is simplifiedif a certain amount of metal, as represented by the longitudinal rib I1,is provided between the millrolls during the bar shaping operation. Thetransverse ribs 18 are added to the bar for the principal purpose ofincreasing the bonding action between the bar'and the concrete orsimilar substance in which it is set and also for the purpose, in someinstances, of increasing the strength or tensile properties of the bar.These ribs may be of different shapes. They may be truly transverse, asshown in Figs. 1 and 3, in the sense that they lie at right angles tothe longitudinal axis A of the bar, or they may be diagonally formed inthe bar, as shown in Figs. 4 to 6, in which case they are, in the senseof this invention, transverse of the bar.

Heretofore when these transverse ribs have been placed upon the bar theyhave extended across the web connecting the two rod-like sections of thebar. In one example of prior art form, such as shown in Fig. 8, thetransverse ribs were placed across the web to strengthen the same aswell as to provide bonding effect, and in this case the ribs 20 did notextend over any large portion of the surface of the rod-like section-sl9.

In another form of bar used prior to this invention, illustrated in Fig.9, the transverse ribs 22 extended over the entire surface of therodlike sections 2| as well as over the entire surface of the web 23. Wehave discovered that the provision of a transverse rib across the webwhich connects the .rod-like sections is detrimental to the performanceof the bar in the concrete.

In accordance with this invention, the transverse ribs extend only oversurfaces, or a portion of the surfaces, of one or both of the rod-likesections of the bar and do not interrupt or extend over the surfaces ofthe intermediate section, or web, of the bar. The differences betweenthe bar of this invention and the bars of the prior art are best shownby a comparison of Figure 7 with Figures .8 and 9, Fig. '7 representinga typical embodiment of this invention. It will be noted that in Fig. '7the transverse ribs extend only over surfaces of the rod-like sections26 and do not interrupt the surfaces of the web or intermediate section21, whereas in Figs. 8 and 9 the web section is interrupted by thetransverse ribs. The advantage and benefits of the bar of this inventionover the bars previously used lie in the fact that there is no pocketformed, when the bar stock is twisted, which will trap moisture, air orany liquid or gaseous media when the bar is set in the construction formand the concrete rises around the bar. in the use of twisted reinforcing'bars which embody transverse ribs which pass across the Web orintermediate section,- the pocket formed between the rib and the surfaceof the web section during twisting will trap moisture and air during thetime that the concrete is being pouredaround the bar. This moisture orair thus trapped prevents a complete concrete-metal contact in the areaof the pockets and, therefore, diminishes the bonding strength of thetotal bar. the air and moisture thus trapped therein attack, in arelatively short time, the surface of the metal "bar, which is usuallysteel, and start acorrod-ing or oxidizing process at that point whichmay finally utterly destroy the cross-sectional integrity of the bar orat least diminish its strength and consequently the strength of thereinforced structure of which it is a part.

Figp'lO, showing in perspective a section of bar stock such as shown inFig. 1 twisted into a reinforcing element, when compared with Fig. 11,which shows in perspective a portion of the bar stock illustrated inFig. 9 twisted into a reinforcing element, illustrates the advantageousdifferenceswhich are obtained-when, in accordance with this inventionthe surface of the web is uninterrupted by the transverse ribs otherwiseprovided on the surface of the rod-like section-s. Referring to Fig; 11,the twisting of the bar stock into the form of a twisted reinforcingelement We have discovered that Moreover,

has caused the ribs 22 to slope sharply where they pass over the websurface 23, thereby forming pockets 3!) which trap moisture-laden air.or moisture and air as the concrete rises upwardly around the bar,whereas, the bar shown in Fig. 10 does not, when twisted, form pocketsover the web It since the ribs I8 terminate at a point short of thesurface of the web Hi. It will be noted that the benefits and advantagesof this invention are realized no matter what may be the peripheral orcross-sectional shape of the transverse ribs and no matter what may bethe spacing of the ribs with respect to the longitudinal axis of the baror with respect to each other, so long as the surface of theintermediate section or web which connects the two rod-like sections ofthe .bar is not substantially interrupted by the transverse ribs. Thetransverse ribs may terminate on the surface of the rod-like sectionsomewhat short of the surface of the web section, or the ribs may blendinto the edge of the web section, but, in accordance with the principlesand teachings of this invention, the transverse rib is not disposedacross the surface of the web section.

The reference to specific forms and shapes in the foregoing descriptionhas been by way of example and with no intention of excluding suchequivalents as fall within the intent and spirit of the invention andthe language of the appended claims.

We claim:

1. A bar adapted to be twisted around its longitudinal axis to form areinforcing element, said bar comprising two elongate rod-like sectionsjoined in substantialy parallel alignment by an integral web ofcross-sectional area less than the cross-sectional area of either ofsaid rod-like sections and outwardly extending integral transverse ribsspaced at intervals on the surface of said bar, the surface of saidintegral web being uninterrupted by said ribs.

2. A bar adapted to betwis-ted around its longitudinal axis to form .areinforcing element, said b-ar, comprising two elongate rod-likesections joined in substantially parallel alignment by an integral webof cross-sectional areailess than the cross-sectional area of either ofsaid rod-like sections and outwardly extending ribs integral with thesurface of said elongate rod-like sections and transversely spaced atintervals thereon, said ribs merging into the surface of said rod-likesections so that the said integral web has asurface/uninterrupted bysaid ribs.

3. A twisted reinforcing element comprising two elongate rod-likesections longitudinally joinedl'by an integral web, said element beingtwisted about its longitudinal axis into a helical structure comprisingtwo helices .having a common axis and outwardly extending integraltransverse ribs spaced at intervals on the surface of said; element andmerging into the surface of.

said rod-like section, the surface of'said web being uninterrupted bysaid ribs.

ODD WENNBERG. JOSEPH 'D. STITES.

